Dual fueled engine with temperature switchover

ABSTRACT

A duel fueled motor using a liquid fuel such as gasoline and a gaseous fuel such as LPG or pressurized natural gas with one or two exhaust treating devices in the exhaust system that operate efficiently when above a selected temperature in treating exhaust from gasoline powered operation, a thermally sensitive controlled changeover from gas to gasoline when the treater reaches a desired temperature and switches back to gas fuel when below a desired temperature.

United States Patent 91 Walker 1 Feb. 27, 1973 i 1 DUAL FUELED ENGINEWITH TEMPERATURE SWITCHOVER [76] Inventor: Brooks Walker, 1280 ColumbusAvenue, San Francisco, Calif. 94133 [22] Filed: June 1, 1971 [21] Appl.No.: 148,545

Related US. Application Data [63] Continuation-impart of Ser. No.17,167, March 6,

1970, abandoned.

[52] US. Cl ..60/285, 123/121 [51] Int. Cl. ..F02b 75/10 [58] Field ofSearch .123/27 GB, 120, 121, 127, 136;

[5 6] References Cited UNITED STATES PATENTS 6/1935 Davisson ..123/121Primary Examiner-Douglas Hart Attorney-Brooks Walker [57] ABSTRACT Aduel fueled motor using a liquid fuel such as gasoline and a gaseousfuel such as LPG or pressurized natural gas with one or two exhausttreating devices in the exhaust system that operate efficiently whenabove a selected temperature in treating exhaust from gasoline poweredoperation, a thermally sensitive controlled changeover from gas togasoline when the treater reaches a desired temperature and switchesback to gas fuel when below a desired temperature.

4 Claims, 3 Drawing Figures PATENTEBFEBZTIQYK 3 718,QOQ

INVENTOR. BROOKS WALKER DUAL FUELED ENGINE WITH TEMPERATURE SWITCIIOVERThis case is a Continuation-impart of Ser. No. 17,167, filed Mar. 6,1970 and now abandoned, for DUAL CARBURETORS FOR DUAL FUELS, insofar asthe material common to both is concerned.

One object of the invention is as stated in the abstract as the exhaustof a cold engine or an engine while warming up to desired temperaturehas less emissions when operating on gas than when operating ongasoline. If the warm up of the catalyst exhaust treater is on gas whilethe engine is warmed up and when warm enough the engine is automaticallyswitched to gasoline operation, the exhaust emissions will then bewithin the present legally prescribed limits with the catalyst treateroperating at or above the desired temperature.

Another object is to have such automatic switchover powered by suctionfrom the intake of said engine with a storage reservoir for suction toprovide suction when operating at or near wide open throttle. Also, aspring in the switchover will result in all starts being on gas whenstarting cold even with insufficient suction to .operate the switchovermechanism during cranking if no spring were used, the reservoir holdingsuction when operating on gasoline after warm up for a limited time.

Another object is to conserve the gas supply and only use it whilewarming up for the first few minutes until the converter can operateefficiently.

Another object is to provide an electrically powered switchover in orderto have a suitable changeover before sufficient engine suction isdeveloped for the switch to gas operation when starting cold. Suctionafter standing a' long time might be insufficient to switch fromgasoline to gas operation for a cold start on gas. Gas makes a betterstarting fuel with lower exhaust emissions with a cold motor than whenoperating on gasoline. A snap thermally sensitive electric switch may besimpler than a snap action vacuum valve.

Another object is to provide a switchover means which will work whethertwo carburetors-one for gas and one for gasoline-are used or whether acombination carburetor with one throttle for operation on gasoline orgas.

Other features will be pointed out in the accompanying specification andclaims.

I have illustrated my invention by way of example in the accompanyingdrawings, in which:

FIG. 1 is a side elevation partly in section and partly schematicshowing one form of the invention.

FIG. 2 is a side elevation of the control in another position.

FIG. 3 is a side elevation partly in section and partly schematicshowing another form of control for switching from gas to gasoline andvice versa, with a combined gas and gasoline carburetor with suitableshut off controls.

In all forms like numerals of reference refer to corresponding parts.

In FIG. 1 and FIG. 2 I have shown an engine with an intake manifold 11.A choke 16 operates between the air cleaner 9 and venturi 13 which hasthe proper fuel feeding (not shown) from the fuel in bowl 14. A throttle17 is mounted on the usual rotatable shaft 18 and controlled by arm 19.A shut off butterfly valve 23 is mounted on rotatable shaft 24.controlled by arm 25 calibrated openings 70a and 7017 so that when arm71 I moves in connection with the movement of control arm 76 forthrottle 75 through rotata'bleshaft 74, the correct amount of gas fromhigh pressure pipe 65 will enter area 61 after being reduced in pressureby the usual controls 63 and 64, as described in S.A.E. Report No. 00078 presented at Auto Engineering Congress, Detroit, Mich., Jan. 2-16,1.970, FIG. 1 per copy attached. A shut off solenoid 64a is controlledby switch S which completes the ground to turn on the gas when stop 26amoves to the left to open valve 79 for gas operation. Power to operatecomes from battery 15 through ignition switch 15.

Control rod 21 connects control arm 76 for throttle of gas carburetor 60to work in unison with throttle 17 of gasoline carburetor 12. Gascarburetor shut off butterfly 79 is mounted on shaft 77 and controlledby arm 78.

Arm 78 is connected to arm 25 by control rod 26' so that when rod 26 ismoved to the left, as shown in FIG. 1, gas shut off valve 79 and thevalve operated by solenoid 64a will be wide open for operating on gascarburetor 60 and gasoline shut off valve 23 will be tight closed, asshown in FIG. 1, to shut off operation on gasoline and operate on gascarburetor 60 and gas flow to carburetor 60 will be open by theoperation of solenoid 64a when switch S forms a ground.

Exhaust manifold 6 is connected to first treatment device 80 and ifnecessary to a second treater and then muffler to tailpipe 90a.

When the sensor 81 in exhaust treatment device 80 gets up to the desiredtemperature, the hot wax on other sensing material or mechanisms in 81will move the joint 42 above the line joining joints 40 and 49. A snapaction'by spring 48 acting on washers 46a and 47a will result to snapplunger 57 of valve 56 to the lower position as shown in FIG. 2 to allowengine suction from line 53 to pass valve plunger Section 57a to line 61to the right of diaphragm 71 in suction operated motor 71 to quicklyswitch control rods 27 and 26 to the right (as viewed in FIG. 1) toclose valve 79 and the valve operated by solenoid 64a and open valve 23to close off gas carburetor 60 operation and operate the engine ongasoline carburetor 12 with efficient treatment of the gasoline exhaustby preheated catalyst in treatment 80 and 85 before going out tailpipe904. To assure adequate suction to provide the desired switchover tooperation on gasoline when treatment 80 is up to temperature, areservoir 55 is between hose 53a and 53 with a check valve CV, betweenreservoir 55 and intake 1 to hold suction in reservoir 55. 1

When treatment device 80 is below the desired temperature sensingmaterial in sensor 81 will contract and pivot 42 will drop below theline connecting pivots 40 and 49. Spring 46 will snap joint 49 up andsnap valve 57 to the upper position, as shown in FIG. 1, so the enginewill operate on gas carburetor 60 until switched to gasoline operated oncarburetor 12 as described previou'sly. Valve 56 provides a bleed 56afor line 66 in the position shown in FIG. 2 and bleed] 56b (Space aroundstem 57c) for line 61 when in the position shown in FIG. 1.

In FIG. 3 we have a motor 7 with intake manifold 1 1. Exhaust manifold 8leads to first treatment 80, then to second treatment 85, muffler 90,and out tailpipe 90a. Thermally sensitive snap switch 81 senses thetemperature inside first treatment 80 by element in 81a and operatesinsulated contact 88 which when treatment 80 is below the desiredtemperature contacts point 87 is contacted by contact 88 and is free ofpoint 89 (as shown in FIG. 3) so that line 100 brings electric powerfrom battery 91 through ignition switch 92 to the ignition system 99 andto insulated contact 88 by a flexible portion 100a. Wire 101 isconnected to point 87 to energize solenoid 98 to open gas flow valve 99to the engine. Valve 85 will be closed until energized to close gasolineflow to the main jet by line 83 and to the idle jet by branch line 83ato close off gasoline flow from the float bowl of carburetor 82 to theair passing through carburetor 82. When engine 7 is below tem peraturesolenoid 98 will be energized as points 88 and 87 are closed, so gascontrol valve 102 will be open for operating on gas until firsttreatment 80 is up to the desired temperature. When the desiredtemperature is reached by treatment 80 as sensed by 81a, insulatedelement 88 snaps over to the right, as viewed in FIG. 3, to contactpoint 89 to energize solenoid 84 to open gasoline flow control valve 85and gasoline will flow to main jet line 83 and idle line 83a throughvalve 85. Gas flow will be cut off by the cutting of current to solenoid90 (which closes valve 91 when not energized). The engine 7 will thenoperate on gasoline as long as exhaust treatment in 80 is above thedesired temperature.

This construction allows the use of electric solenoids controlled byvery limited action of the temperature sensitive element 81a in theexhaust treatment device 80 to control the operation of the engine tooperate on gas below the desired temperature at exhaust treatment 80 andthen automatically switch to gasoline operation with a single dualedfueled air and gas mixing device or gasoline fed carburetor 82 andallows two fuels to use a single power controlling throttle 97 for bothfuels when supplied separately.

The electric control circuit shown in FIG. 3 could be used to controlthe shut off valves 79 and 23 of FIG. 1, if suitable solenoids somewhatlike 84 and 98 are used to control the motion of rod 27 to-shift fromgas operation below a desired temperature of treatment 80 to gasolineoperation when above said desired temperature of 80 as sensed by element81a. Solenoids and valves which are closed when energized instead ofopen when energized could be used by changing the switching if this weredesirable.

Other features will be pointed out in the accompanying claims.

I have illustrated my inventionsin these various forms; many othervariations may be possible within the scope of this invention.

To those skilled in the art to which this invention relates many changesin construction and widely differing embodiments and applications of theinvention will suggest themselves without departing from the spirit andscope of the invention. The disclosures and description herein arepurely illustrative and are not intended to be in any sense limiting.

I claim:

1. An engine having dual air and fuel mixing devices for feedin saidengine, said mixing devices adapted to feed liqui fuel such as gasolineor gas fuel, such as LPG or gas from a pressurized container, means forswitching the feeding of the fuel to the engine from one mixing deviceto the other, an exhaust system, a treatment device in said exhaustsystem, said treatment device operating better above a desiredtemperature than below said temperature, a temperature sensing devicedisposed to sense the temperature of said treatment device, and meansoperated by said temperature sensing device for controlling theswitching means to cause the feeding of said engine with gas fuel whenthe treatment device is operating below a selected temperature and toautomatically cause the feeding of said engine with gasoline when saidtreatment device is above said temperature said means operated by thetemperature sensing device also controlling the switching back to gasfueled operation of said engine when said treatment is below the desiredtemperature.

2. An apparatus for operating a dual fueled internal combustion enginehaving an intake manifold and an exhaust system, a treatment device inthe exhaust system, a thermally sensitive device disposed to sense thetemperature of said treatment device, automatic means responsive to saiddevice for shifting said engine to operate on a gaseous fuel when saidtreatment device is below a selected temperature as sensed by saiddevice, said device controlling the automatic means to shift said engineto operate on a liquid fuel from operating on said gaseous fuel whensaid device is above a selectedtemperature of said treatment device.

3. A device as defined in claim 2, in which the power means to operatesaid automatic means for shifting from operation of said engine on onefuel to the other fuel, the power for energizing the power means beingderived from the suction from said intake manifold of said engine.

4. A device as defined in claim 2, including electrically powered motorsfor operating the automatic means for shifting from operation of saidengine on one fuel to operation on the other fuel, said motors beingcontrolled by said sensing device associated with said treatment device.

1. An engine having dual air and fuel mixing devices for feeding saidengine, said mixing devices adapted to feed liquid fuel such as gasolineor gas fuel, such as LPG or gas from a pressurized container, means forswitching the feeding of the fuel to the engine from one mixing deviceto the other, an exhaust system, a treatment device in said exhaustsystem, said treatment device operating better above a desiredtemperature than below said temperature, a temperature sensing devicedisposed to sense the temperature of said treatment device, and meansoperated by said temperature sensing device for controlling theswitching means to cause the feeding of said engine with gas fuel whenthe treatment device is operating below a selected temperature and toautomatically cause the feeding of said engine with gasoline when saidtreatment device is above said temperature said means operateD by thetemperature sensing device also controlling the switching back to gasfueled operation of said engine when said treatment is below the desiredtemperature.
 2. An apparatus for operating a dual fueled internalcombustion engine having an intake manifold and an exhaust system, atreatment device in the exhaust system, a thermally sensitive devicedisposed to sense the temperature of said treatment device, automaticmeans responsive to said device for shifting said engine to operate on agaseous fuel when said treatment device is below a selected temperatureas sensed by said device, said device controlling the automatic means toshift said engine to operate on a liquid fuel from operating on saidgaseous fuel when said device is above a selected temperature of saidtreatment device.
 3. A device as defined in claim 2, in which the powermeans to operate said automatic means for shifting from operation ofsaid engine on one fuel to the other fuel, the power for energizing thepower means being derived from the suction from said intake manifold ofsaid engine.
 4. A device as defined in claim 2, including electricallypowered motors for operating the automatic means for shifting fromoperation of said engine on one fuel to operation on the other fuel,said motors being controlled by said sensing device associated with saidtreatment device.